From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f178.google.com (mail-lb0-f178.google.com [209.85.217.178]) by kanga.kvack.org (Postfix) with ESMTP id AC7AC6B0036 for ; Fri, 27 Jun 2014 14:57:37 -0400 (EDT) Received: by mail-lb0-f178.google.com with SMTP id 10so4238011lbg.23 for ; Fri, 27 Jun 2014 11:57:36 -0700 (PDT) Received: from mail-la0-f50.google.com (mail-la0-f50.google.com [209.85.215.50]) by mx.google.com with ESMTPS id lc2si10619139lab.131.2014.06.27.11.57.35 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 27 Jun 2014 11:57:36 -0700 (PDT) Received: by mail-la0-f50.google.com with SMTP id pv20so3237457lab.37 for ; Fri, 27 Jun 2014 11:57:35 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <53ADACF7.7080203@intel.com> References: <1403084656-27284-1-git-send-email-qiaowei.ren@intel.com> <53A884B2.5070702@mit.edu> <53A88806.1060908@intel.com> <53A88DE4.8050107@intel.com> <9E0BE1322F2F2246BD820DA9FC397ADE016AF41C@shsmsx102.ccr.corp.intel.com> <9E0BE1322F2F2246BD820DA9FC397ADE016B26AB@shsmsx102.ccr.corp.intel.com> <53AB42E1.4090102@intel.com> <53ACA5B3.3010702@intel.com> <53ACB8A7.9050002@intel.com> <53ADAB39.6030403@intel.com> <53ADACF7.7080203@intel.com> From: Andy Lutomirski Date: Fri, 27 Jun 2014 11:57:15 -0700 Message-ID: Subject: Re: [PATCH v6 02/10] x86, mpx: add MPX specific mmap interface Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: "Ren, Qiaowei" , "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , X86 ML , "linux-kernel@vger.kernel.org" , Linux MM On Fri, Jun 27, 2014 at 10:42 AM, Dave Hansen wrote: > On 06/27/2014 10:34 AM, Dave Hansen wrote: >> I'm claiming that we need COW behavior for the bounds tables, at least >> by default. If userspace knows enough about the ways that it is using >> the tables and knows how to share them, let it go to town. The kernel >> will permit this kind of usage model, but we simply won't be helping >> with the management of the tables when userspace creates them. > > Actually, this is another reason we need to mark VMAs as being > MPX-related explicitly instead of inferring it from the tables. If > userspace does something really specialized like this, the kernel does > not want to confuse these VMAs the ones it created. > Good point. --Andy -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org